Every PR reviewed.
Zero tests written.

DiffFence reads your diff, generates tests, runs them on both branches, and tells you exactly what broke. One command.

$

Understand your diff, test what matters

◎

From code diffs

Reads your PR diff and infers what changed, why it changed, and what could break.

⚙

Auto-generates tests

Creates targeted test scenarios for each changed function. No boilerplate, no maintenance.

★

Zero maintenance

Tests are generated on the fly and discarded after use. Nothing to commit, nothing to maintain.

↺

Always up to date

New tests generated automatically as your code evolves. No stale test suites.

Find real bugs, filter the noise

✓

Multi-layer filtering

Strips type errors, flaky assertions, and import failures. Only real behavioral changes surface.

↻

Self-healing tests

Wrong expected value? DiffFence reads the error, fixes the test, and re-runs automatically.

⚡

Fast feedback

Results in seconds, not the minutes of full E2E suites. Runs on both branches in parallel.

✕

Latent bug detection

Finds bugs that existed before your PR. Flagged separately so they never block your merge.

Every bug comes with a root cause

🔍

Root cause, not stack traces

Every failure includes the exact code path, file, and line that caused the regression.

⚖

Confidence scores

Each finding includes a confidence percentage so you know which bugs to fix first.

📈

Impact assessment

Shows blast radius — how many code paths and downstream functions are affected.

💬

Inline PR comments

Auto-posts review comments directly on your pull request with bug details and suggested fixes.

Simple pricing.

No tiers. No credits. No confusion.

$ 2 / PR

Everything included. Pay only when DiffFence runs.

  • ✓ Up to 30 functions analyzed per PRCovers even large pull requests
  • ✓ Up to 200 lines per functionFull context for accurate analysis
  • ✓ Auto-posts review comments on your PRInline comments with bug details and confidence scores
  • ✓ Self-healing tests & noise filteringOnly real behavioral regressions surface
  • ✓ Works with GitHub ActionsOne-click GitHub App install. Zero config.
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Be the first to catch bugs before they ship. Limited early access spots.